1. Field of the Invention
The present invention relates to an injection-molding metal mold used for molding a body having a high-precision portion by injection molding, and a body molded by using the metal mold more particularly, the invention relates to an injection-molding metal mold which can be suitably applied to, e.g., molding grooves that form ink flow channels of a liquid jet recording head having a grooved precision portion for flowing ink to discharge ports, so that ink droplets are discharged from the discharge ports to perform recording.
2. Prior Art
The present applicant previously proposes an ink-jet recording apparatus to which a liquid jet recording head integrally formed with an ink container is detachably mounted to improve the operability and to facilitate maintenance.
This ink-jet recording head is formed as a top plate component 400, which is an integral molded body as shown in FIGS. 9 and 10, integrally having a recessed portion 430 for forming a common ink chamber, multiple groove portions 411, 412, . . . (only two are indicated by broken lines in FIG. 9) for forming ink flow channels communicating with the recessed portion 430, and an orifice plate portion 404. Ink discharge holes 421, 422, . . . are formed in the orifice plate portion 404 by a laser boring device or the like.
In this manner, the top plate component 400 is integrally formed simultaneously with the orifice plate portion 404 in a metal mold. To form the groove portions 411, 412, . . . for the ink flow channels, a molding portion, in which small grooves having a shape opposite to that of the groove portions are formed by cutting or the like, is formed in the cavity, and a resin is injected. As a result, the molded body of the top plate component 400 is obtained.
A heater board 100 having a discharge heater 105 and the like is abutted against the top plate component 400 obtained in this manner, and they are bonded to obtain a complete recording head body, as shown in FIG. 10.
The sizes of the respective portions of the recording head which is completed through the process described above are determined in accordance with the printer specifications. For example, when the dot recording density is high, the groove width of the groove portions 411, 412, . . . is set to 32 .mu.m (micron), and the width of a non-groove portion is set to 31.5 .mu.m. As a result, the width of the projecting portions of the metal mold corresponding to the portions to define the groove portions 411, 412, . . . is set to 31.5 .mu.m.
In order to mold a body having small grooves as described above, a high-temperature molding method is conventionally performed. According to this method, a metal mold is kept at a high temperature to increase the flowability of the resin material, so that the resin material in the molten state can reliably reach the small groove portions to run in the molding portion, thereby performing injection molding.